How does table log_link_visit_action update?

Support & Bugs
1

I find that table log_link_visit_action will update even after one month.

for example, following sql result changes every day while I see same date ‘2016-08-01’

select cast(server_time as date),count(1) ,count(distinct idvisitor),count(idvisit)
from ahs_tk.ahs_log_link_visit_action
JOIN ahs_tk.ahs_log_action
on ahs_log_action.idaction=ahs_log_link_visit_action.idaction_url
where ahs_log_action.type=1
group by cast(server_time as date)